The present invention relates to the application of ceramic coatings on substrates. The method comprises applying a preceramic coating comprising hydrogen silsesquioxane resin, a material containing Si--Si bonds which forms volatile SiH compounds, and a catalyst followed by pyrolyzing the preceramic coating in an inert atmosphere. The novel ceramic coatings formed by the process of this invention are especially valuable on electronic devices.
The use of ceramic coatings on various substrates, including electronic devices, is known in the art. For instance, Haluska et al. in U.S. Pat. No. 4,756,977, which is incorporated herein in its entirety by reference, disclose ceramic coatings produced by applying solutions of hydrogen silsesquioxane resin to a substrate and then ceramifying by heating to temperatures of 200.degree.-1000.degree. C. It is taught therein that the resultant ceramic coatings have many desirable characteristics which make them valuable as protective and insulating layers on electronic devices.
Haluska in European Publication No. 0427395 published May 15, 1991, also describes a process for applying ceramic coatings on substrates comprising forming a hydrogen silsesquioxane resin preceramic coating on a substrate and then pyrolyzing it in an inert atmosphere at temperatures of 500.degree.-1000.degree. C. This process is described therein as being valuable for the application of ceramic coatings on substrates prone to oxidation.
The present inventors have now unexpectedly found that a material containing Si--Si bonds which forms volatile SiH compounds and a platinum or copper catalyst can assist in the conversion of hydrogen silsesquioxane resin to novel ceramic coatings.